NREL Expands Biofuels Partnerships

February 28, 2011

NREL's Daniel Schell stands in the open high bay near an acid impregnator in the IBRF. The new facility will accommodate biofuels pretreatment with alkalis as well as various dilute acids.
Credit: Dennis Schroeder

The scenario for your business dream plays out like this. You have an idea to make a fuel from biomass using a biochemical conversion processes. You and your investors have completed bench-scale tests of your process, but now it is time to take it to the next level and process up to one ton of dry biomass a day. However, in a tough economy you don't want to build your own demonstration facility, but still need somewhere to test it. It turns out that "somewhere" is located at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL).

This past year, NREL completed construction on phase one of its Integrated Biorefinery Research Facility (IBRF) and phase two is currently underway. The idea for the IBRF is deliberate — a place for NREL and industry to test demonstration-scale projects and speed the commercialization of biofuels.

"The IBRF is designed specifically to help industry scale up their technology," NREL Team Leader for Partnership Development John Ashworth said. "We have created an empty bay in the facility so someone can bring in their own pretreatment reactor or other equipment required for biochemical biomass conversion. Companies can use part of our system or they can use their own technology and we can run it in parallel with ours. That way, they can see if their system is better than ours."

NREL's creation is a $33.5 million pilot plant and facility upgrade capable of supporting a variety of advanced biofuels projects. The IBRF boasts a 27,000 square foot high bay with one area where industry partners can bring in and test equipment, as well as upgraded laboratories, additional office space, and access to NREL expertise. The IBRF also features enhancements to NREL's existing biochemical pilot plant which now includes:

Three parallel front-end process trains for pretreatment through enzymatic hydrolysis

The ability to do research on pretreatment using a range of pH conditions

The capability to handle high solids concentrations through enzymatic hydrolysis.

"Industry partners can come in and try whatever they might have in mind from a very mild pretreatment to a very strong pretreatment and the system is set up for that," Ashworth said. "The high solid enzymatic hydrolysis reactors sit directly beneath the pretreatment reactors. All of this allows us to really push the limits of how you can use the system and still get to sugars."

NREL's pilot plant has been serving the lab for more than a decade and researchers have made significant discoveries along the way. But, putting that new-found knowledge to the test was becoming a challenge. "Our existing pilot plant was at capacity, we no longer had room to add equipment," NREL Manager for Bioprocess Integration R&D Dan Schell said. "We've learned a lot over the years but didn't have the capacity to expand the pilot plant and add more equipment or newer cost-effective technology."

Flexible Facility Welcomes Many Treatments

NREL's John Ashworth says the new IBRF is "designed specifically to help industry scale up their technology."
Credit: Dennis Schroeder

Taking that as a lesson learned, flexibility has become a key word when NREL staff discuss the capabilities of the IBRF.

"We looked at how could we upgrade the pretreatment systems to meet current and future needs and test a wider range of reaction conditions," Schell added. "The new system can operate at residence times as low as several minutes up to two hours. This gives us the ability to support a wide range of pretreatment catalyst options, including dilute acid and alkali-based treatments."

Researchers also can use the IBRF to conduct high solid enzymatic hydrolysis. The ability to test biochemical processes using high solids is a key metric for increasing biofuel concentrations and decreasing production costs.

"In the IBRF, we have two large batch mixers that perform high solid enzymatic hydrolysis," Schell said. "Once we liquefy the biomass in the high solids reactors, we can pump it into a conventional stirred tank reactor and finish converting biomass to sugars. This gives us the capability to perform enzymatic hydrolysis at commercially relevant solids levels."

Although research in cellulosic ethanol derived from corn stover — the stalks, leaves and cobs — is a focus for research at NREL, the new capabilities of the IBRF open the doors to all types of fuels research. "The IBRF is not restricted to one end fuel," Ashworth said. "The technology here will work just fine if someone wants to make butanol or take lignocellulose and go to jet fuel or diesel. All of these technologies on the biochemical side use pretty much the same front-end pretreatment and enzymatic hydrolysis equipment."

NREL Does Some Extra Investigation

NREL employees Bob Lyons and Cindy Gerk inspect the biomass pretreatment reactor at the IBRF, which is capable of supporting a variety of advanced biofuels projects.
Credit: Dennis Schroeder

Working with DOE's Office of Biomass Program, the IBRF will help NREL researchers gather data that demonstrates the achievement of U.S. goals for cellulosic ethanol cost targets. It is now a race against the clock with the goal for cellulosic ethanol to be cost competitive with corn grain ethanol by 2012. Longer-term goals outlined in the Energy Independence and Security Act of 2007 (EISA) require that the U.S. use 36 billion gallons of renewable fuels by 2022, all in an effort to offset U.S. dependence on foreign oil.

"The idea is for us to facilitate industry success by showing that it is possible to achieve these conversion goals, and that, with the right circumstances, industry can have more confidence in their ability to commercialize the technology," Schell said.

Right now many along the path to commercialization are focusing on the big three operation units — pretreatment, enzymatic hydrolysis and fermentation. According to Schell, there are other issues that NREL is beginning to tackle, including looking at the liquid effluent that comes out of the various biochemical conversion processes. "We also are facilitating success of industry by being able to explore the less glamorous research issues that may have a huge impact on process economics," Schell said.

The advantage to NREL doing some of the nitty gritty work at the IBRF is that the lab can provide high level information to all industry players letting them know what's in a possible waste stream, what can be done to treat it, and the costs.

"Industry can take that initial information and see how it will impact their economics," Schell said. "It's an issue that people ultimately are going to be highly concerned about but, right now, they are focused on understanding and improving performance of the major unit operations."

"I think the important thing about the IBRF is to understand that government is never going to commercialize this technology," Ashworth added. "It is a transition from a bench scale system which is cheap to run. Then the IBRF is set up to be the facility where you can prove your technology at an engineering or demonstration scale before getting the investment capital to build a large factory."